Air-pressure operated drawer clamping machine



Jan. 22, 1952 J. M. LANCASTER AIR-PRESSURE OPERATED DRAWER CLAMPING MACHINE 4 Sheets-Sheet 1 Filed Aug. 24, 1950 w u w m m INVENTOR ATTORNEYS Jan. 22, 1952 J. M. LANCASTER AIR-PRESSURE OPERATED DRAWER CLAMPING MACHINE 4 Sheets-Sheet 2 Fil ed Aug. 24, 1950 dmlarzcamiefi INVENTOR P OOOOOOOLi ATTORNEYS Jan. 22, 1952 J LANCASTER 2,583,219

AIR-PRESSURE OPERATED DRAWER CLAMPING MACHINE Filed Aug. 24, 1950 4 Sheets-Sheet 3 J M. Lancaa Z27 INVENTOR ATTORNEYS Jan. 22, 1952 LANCASTER 2,583,219

AIR-PRESSURE OPERATED DRAWER CLAMPING MACHINE Filed Aug. 24, 1950 4 Sheets-Sheet 4 INVENTOR ATTORNEYS Patented Jan. 22, 1952 U ITED- STATE- S PATENT OFFICE AIR-PRESSURE OPERATED: DRAWER CLAMPING ,MACHINE.

JterML Lancaster, High Point, N. C.

Application-August-M, 1950; SerialNo. 181,303

This invention relates toapparatus used'lin the art of. furniture construction forv assembling More. particularly, the invention has.

drawers. reference to an improved. draw clampingjrna= chine of the type shown for example, inmy prior Patent No. 2,114,390, issued :April 19,-,19381 It isan. important object" ofthe present invention to provide a generally improved: con-'- struction for the drawer clampi'ng,machine;

Another important object is to provide an'im will requiretheback of 'the drawerto Depressed.

from another direction after thefdrawer front has alreadyv been pressed upwardly.

Another importantob'ject is to provideanimproved construction wherein the clamping jaws are adiustedto operative positionby an improved means comprising spaced screws linked for joint operationby. means of a crankmhain, andi'spaced sprockets With the foregoing and other objectsin View whichwill appear as the description proceeds,

the invention consists of certain novel-details of construction and combinations of 'parts, hereinafter more fully. described" and pointed out 3 in the. claims, it' being. understood that changes may be made in the construction and'arran'gefFi'g. 451s. a section'substantially' on"1ine 11-4- ofFig. 3.

Fig. 5 is a perspective view'of the back clamp ing bar of oneof the jaws.

Fig. 6 is a fragmentary perspective"view*show-- ing a portion of said back clamping bar "andof a. drawer'engag'ed thereby showing how the drawer'bottom is inserted.

Fig; '7 is a fragmentary'rear elevationof'the' back clampingbar:

Fig. 8 is a top plan'fv'iew nawing the b'a'ck clamping barin position over a drawer:

Fig; 9 'is a fragmentary secticn' taken substantialiy on line 9--*9 of Fig: T.

Fig. 10 is a sebtion substantially on line I 0-| 0' or Figi3.

Fig. 11 is asomewhat diagrammatic side eleva' tion ofthe clamping assembly'as it appears when applied. to a. drawer with a halflswelled front.

Referring. to thedrawings in detail, the machine. constituting, the present. invention is mounted 'upon a supportingv frame including the legs I suitably cross braced andl braced longltudinally asat. 2.

Side. rails 3 are rigidlysecured to the upper ends of the legs I and extend longitudinally of the-frame inspaced. parallel relation. On the respectivev side. rails. are rigidly mounted elonated flanges 4'each of which is formedwith" a longitudinal series of openings 5.

Flanges! constitutea slideway for the movable-r jaws, in a manner to be madepresently apparent.

Mountedupon theouter surfaces of the side rails 3 and underlying the respective flanges 4" are the bearings. 6. and. l-having smooth walled bores-in which are supported for rotation elongated screws 8 said. screws projecting beyond one end of :the supportingframe and being. there provided with sprockets. aroundwhich passes a chain 9 linking the. screws for simultaneousro= tation. A crank Ill-is mountedupon oneofthe sprockets.- The screwsare forthe purposeof shifting one-of the clamping. jaws longitudinally oftheframein either direction,. this being the jaw shownat-the left in Fig. land which for purposes of clarity in description .will. hereinafter be termedthe left jaw.

Depending from opposite. sides of the. left jaw at the bottom end thereof arefollowerslfl in the form of internally; threaded. sleeves that are threadedly engaged with the. respective advanc ingscrews 8. Therefore, rotation ofcrank 50 in either." direction will shift the sleeves l0 longitudinally of the supporting frame .in either. direction. The: sleeves lilare. alignedfltransversely. of the supporting frame.

Thesleeves l0 arerigidly secured to the undersides of guide plates li that underlie the-respective flanges land are slidabletherealong. The guide plates ii are removably secured to opposite sidesofa carriage l2 constituting.thelower portion of the jaw-and straddling thesupporting. frame. The carriage l2 overlies and is slidable upon-the guide flanges 4, and thus the "carriage lZ' is mounted for sliding movement-longitudinally of the supporting frame.

At this point; it should. be noted that the left jawis identical to the right handjaw' shown in Figs: 1 and 2; except forbeingoppositely disposed. Therefore, the" description" of the left jaw will sufiioe for and be understood as applicable to. the right jaw. The main difference in the jawsresides in the fact that the guide plate i3: of the right j aw is not connected to the-screw for threaded advancement of the right jaw. Instead, the right jaw is freely slidable upon the slideway.

Referring once again to the left jaw, a primary adjustment of said jaw is made longitudinally of the supporting frame by operation of the crank l0. Thereafter, stop pins are dropped into the openings 5 immediately behind the jaw each stop pin including a knurled upstanding handle 14 connected to a bracket i5 rigid with the depending stud l6 extendable into a selected opening 5.

Threadable horizontally through the bracket l5 and against the carriage I2 is a fine adjustment screw ll. Thus, when the carriage i2 has received its primary adjustment, the stop pins are dropped into suitable openings immediately in back of the carriage, after which the screws I! are threaded against the rear surface of the carriage. These thus serve as stop means whereby all pressure applied against the jaw in a horizontal path will not be shouldered by the threads of the advancing screws 8.

Integral or otherwise made rigid with the front surface of the carr age I 2 are the transversely disposed horizontal draw front clamping bars I8, 19, and 20. As seen from Fig. 1, these are vertically spaced and each extends transversely across the supporting frame substantially from side to side of said frame.

Mounted upon the carriage l2 and upstanding therefrom a substantial distance is a cast standard 2| which, as readily seen from Figs. 4 and 10, is preferably of U-shaped cross section, this channeled construction being preferable for imparting strength to said standard.

An adjusting screw 22 is disposed vertically in the standard as best seen from Fig. 3, the ad usting screw projecting above the top end of the standard and being there provided with a, hand wheel 23. The upper end of the screw is smoothwalled and bears in a smooth-walled opening 24 formed in the upper end of the standard.

Threaded upon the lower end of the screw 22 is an adjusting nut 25 underlying a slide 26 having the rearwardly extended projection formed with a smooth-walled opening 2! through which the screw 22 extends. Thus, the slide 26 can slide up and down upon the screw but is not threadedlv engaged therewith.

The slide is mounted for vertical sliding movement in a vertical slot 28 extending substantially from top to bottom of the stand 2!. Up and down movement of the slide is effected by threading of the nut 25 upwardl and downwardly on the screw 22, the underside of the rearward projection of the slide being formed with a recess receiving the upper end of said nut.

Rigidly secured to the slide 25 is a plate 29 straddling the slot 28, said plate 29 extend ng over a pair of guide flanges 29' formed upon the standard 2| and extending vertically to provide a slideway. Guide plates 30 are removably secured to the flanged side edges of the plate 29 to hold the plate 29 upon the standard during its up and down sliding movement on the standard.

Extended laterally from the opposite side edges of the plate 29, and formed integrally upon the plate, are ears 3| formed with threaded openings in which adjusting screws 32 are threaded, these being disposed horizontally and being each provided, as seen in Fig. 4, with a ball 34 universally movable in a ball socket formed in each end portion of a pressure plate 33.

In any position to which the respective screws 32 are adjustably threaded, they are capable of iii being locked in position by means of a lock nut 35.

It will thus be seen that there is provided on each jaw a drawer side clamp, each clamp being vertically adjustable to a selected position and being provided with a pressure plate horizontally adjustable against a drawer side. A set screw 36 carried by the rear projection of the slide 28 engages the upper extension of the nut 25 to secure the slide 26 to said nut after the nut has been adjusted to a selected position.

In addition to each drawer side clamp, there is also mounted on each jaw a drawer back clamp. This includes a follower 31 having threaded engagement with the screw 22. The follower 31 slides in the slot 28 and. is rigid with a slide member 38 straddling the front of the standard 2| and sliding on the flanges 29' of the standard, the slidable mounting of the member 38 being provided for by the guide plates 39 removably attached thereto and underlying the flanges 29' of the standard.

At this point, it will be apparent that by rotation of the hand wheel 23, both the drawer side clamp and the drawer back clamp will be adjusted vertically of the screw 22, that is, they will be simultaneously adjusted equal amounts up and down the jaw. However, apart from this simultaneous adjustment, the drawer side clamp is independently adjustable, since the nut 25 can be manually rotated to move it up and down the screw 22 while the screw is stationary. This is to permit adjustment of the side clamp and the back clamp relative to each other to accommodate diiferent drawer formations.

Considering the construction of the drawer back clamp, there is rigidly secured to the slide member 38 an air cylinder 40 of conventional construction, this air cylinder being provided with the air pressure operated vertical plunger 4| extending downwardly and threadedly connected to a cross bar 42 the construction of which is particularly well illustrated in Fig. 5. ,A- set screw 42 effectively locks the connection to prevent any rotatable movement of the cross bar relative to the plunger.

The cross bar 42 is provided with rearwardly extended flanges 43 to which are removably connected the guide plates 43, for slidable mounting of the cross bar 42 upon the lower extension 44 of the slide member 38. Thus, the slide member 38 is mounted for up and down slidable adjustment upon the stand 2|, While the cross bar 42 is in turn slidable up and down upon the slide member after the slide member has been adjustably positioned at the desired height.

Pivotally connected at its center to the center portion of the slide 42 is a clamping bar 45 of right angled cross section, having the depending longitudinal flange 46. This pivots in a horizontal plane and regardless of the direction in which it is pivoted, is returned to a normal position as seen in Fig. 5, wherein its front surface is flush with the front surface of the member 42. For accomplishing this I provide, as seen in Figs. '7 through 9, a pair of rearwardly extending pins 41 threadedly connected to the clamping bar 45. these pins extending rearwardly from the clamping bar at opposite ends thereof. Surrounding these pins are springs '48 abutting at one end against the clamping bar and at the other end against depending extensions of the member 43. that is the guide plates whereby the slide member 42 is mounted for up and down sliding movement upon the air cylinder slide 38. Said depending extensions of the guide plates 43 are formed wan-smarts throu h hichsthewpms.

extend: slots. being." utilized at this location in! steadai of: smaller openings in. order to permit lateral-movement oi lthe.pins;relative;..to the guide;

plates wheneverrthe: clamping-bar: 451: is pivoted uponthe slideAZ.

Airopposite sides; of. the; pivotal. mountin thereof, the-clampingr r .55115 :chamiered asset:

50;.f0ra nurpose:;to be: n1'esent1y.- made apparent..

On. :each of 1 thew-jaws l .Eprovide the: Lrshapedsupporting-rods;52,-.mounted1or vertical swings a. ing, n1.overnentx in v(brackets 5 l-, and adapted, to. be

held in any: positionito which. adiustedzbythumh screws .52 Thesezservez asdrawer stops to hold. 4

the sides oi. the: draWer.-- at: any, desired :position while. the drawer is: beings clamped... As will he appreciated, the:1.-'ods-*can be adjusted. byrloosen-E ing the thumb screws: 52 whereupon...thee-rods;

are swung-toe the desired: new position .oi. adl .st, merit: and: aeairrlockedjnposition-1 Q raemh-ofjthecrightand-left laws; I ilioi ide When..- the. screws: 54 have :been threaded-m as selectedv position; they; arelocked in said. position bymeans-of lock nuts 51?- By referenceatm ..2.o--it is. seen. thatian .ar-- rang laments including the. thumb. scre 54. and arm is provided at each sideloi thesjaw, adjai cent the guide flanges 4. Thuathe arms 55pmvide bearings that are spaoegltransversely,oI the supporting iram -ande thatare. swin a x dI- justed upwardly and downwardly, these hearings supporting opposite ends. of @a rock shaftfifi. rigid.

with; the. transversely attending restfill. in. the.

form of a flat. bar adaptodto underlie; a. drawer The= rockable: mounting; 01?; said, resi;,. 59.

front. adapts it to drawer fronts. ofjany. configuration. wl'ietlrerthey.becurved or straight.

When the rest .59 has. been rockably, adjusted. into engagement e with.v the. particular drawer. front, it is. held vin said} position .by. means. offset. screws three-dame through the arms .55 again t therooisshaftfiii...

1 also. provid a' middle rest for: the: drawer front,, which. .insomei-instaheeswvillinot he. ,nec'esi: sary if the .draweris'.;rather short. However; if the draweris long, itis desirable to provide. a. suitable support 1 for the medial portion'xthereoi; to prevent" buckling. or sagging, thereof; when pressureisrapplid to opposite ends of the drawer front by the clamping surfaces iii" of the respectivedrawers,

With: respe t to. t s. medial suppo rally. disposed. between. opposite end 0f.fthe SllPlQ911 the: frame is aevertically threadable... screw 52; threadable throuehea. cross bar. 6.! rigid .withg hfi opposite sideurailse3. A-.10. cknut iii-locks. the. screw 62 int-"selected. positionssoiw threadable-adiustment.

Supported.uoougtheaunper:cruiser ther orew fil Eachof these.includes;adjustingv 6.2 iszai middlereste in the: form; of: a flat barrhavingsraised ends. overlying ,the'zguide. flanges. 4.- A'.fragment off: a drawer 'is illustratedin vfile's.

6 and; 8 respectively and includes; drawerssidess 66, aadrawerl bottom; 51 receivable: inithe; groove 68.101 thedrawersides, and. a drawer": front 59; In. this s connection a drawer. such as is to: be

completely? assembled .in 1 the present apparatus. 1 is generally madecupof five. parts/.1. The drawer front; 69 isiormed withsiemale dovetails alon thebinside edges of .each end of the drawer front. The-:drawerrsidesfifiiare formed with male dove"-- tail'saon their frontedges and withiemaledove- The drawer back, not; illustrated infiFi'gs. 6- and8', is formed.:with-;male

tails at their back ends.

dovetails :atlooth, ends; The drawer bottom fills usuallyasxpiece oi.plywoodzor' similar material;

fitting: into.- atgroove-whioh is out at the bottom: ofithe "drawer-front; drawemback; and the drawerv sides;

Another type-10f drawer-adapted lto be assembled by. the.machineis:illustrated in Fig; 11; In. thisdrawer there isadrawer-back Ill; and drawersidesfli; the-drawer sidescilbeing of unequal.

lengths; in view of1the;.faot that the drawer is 01:

the: half swelledafront type. The. half swelled front is designatedflil, and: as'willbe seen, it is longitudinally? curved toward" one end of the drawer:

The manner inwhich' the drawers are assem--- bled will be zdescribed in rdetail hereinafter.-

Completing the formation of .theapparatus is.

the control and power means thereoi. An air line13 is connectable-toflany source of air toibe supplied under pressure. This air is; directed rockablehfooti pedalwhichgywhen rocked in one:

direction, will: remain. in' the position, to which rockeduntil released by foot pressure-rockingit back' in'i'tsrprevious position;

The air suppliedyunder: pressure inthis :man nerds directed through-hoses1 16-, to anzair pros sure cylinder 1'! mounted uponia suitable bracket beyondfonevend of' thesupporting frame; Theair cylinder 11 'ac'tuates a; plunger 18. engaging. the rear-surface? of the right jaw, so as to forcesaid jaw to-the'leftsin-"Fi'g, 1. Stop pins=19 limit movementi ofi'the" law under; pressure: These stop pins have .two" purposes; One" is to enable the:- operator-tmadiust the length of the. stroke or: the plunger 18 and righthand jaw,: and it will be-apparentthat un -removal of the stop pins .19,

. ailonger'stroke can-be given the j aw. The otherpurposetis to HOZId'QthG I'ightTjaW' perfectly square so'as togive'uniiorm pressure against-the drawer fully transversely-ofthedrawer. As will be seen, not only? do their stop; pins hold the-"drawer perfectly square :in this'manner; but also, they constitutearrestraint that holds the pressureagainst the; drawer: atthe" desired-point without damaging-the= drawer through application thereto of: excessmressure; which otherwise might. result if the restraint dldfnOtneXiSt. and the drawer was.

pressed against by the ri ht-jawunder. thefull pressure; ofrthe'ram or plunger 'lilr Another ainregnlating valve-:Bllkis mounted uponna=line Bil. that alsotextends-from vthe'uair inlet 'l3. This; valve; regulates air to:- befed throughllnes 3| 'tozthe: cylinder 4! of the-left jaw:- Thefeeding oi airtdtheoylinder 46- is controlled by a pfoot pedal 82.

As will be noted, there areesupplylineseilito both of; the cylind rs. 4.0;. so: that air: lSwfBdl'; in

equalized amounts to both of these cylinders simultaneously, by depression of the pedal 82.

Considering now the use of the machine, as previously noted the machine should first be connected to a source of air to be fed under suitable pressure, as a first step, the foot pedal I is shifted to one position, applying pressure to the right jaw to cause said jaw to move toward the left in Fig. 1 against the stop pins 19.

Then, by operation of the crank [0, the left jaw is shifted toward the right in Fig. 1, that is, toward the right jaw, the jointly rotated screws 8 holding the left jaw perfectly square during said movement.

Assuming that the drawer to be assembled has a fiat front 69 as distinguished from a curved front such as that seen in 12, it will be understood that the left jaw will be adjusted until the drawer front can be supported at opposite ends upon the rests 59.

The rests 59 will now be adjusted upwardly or downwardly as necessary until the clamping surfaces 18 of the right and left jaws are in line with the female dovetails of the drawer front and are just above the lips formed at opposite ends of said drawer front. These lips will engage under the clamping surfaces l8.

When this adjustment has been made, the rests 59 are locked in their positions of adjustment by means of the lock nuts 51 and set screws 60.

At this stage, the clamping surfaces l8 of both jaws should be tight against the dovetails of the drawer front.

The next operation is to square the drawer side clampin bars 33 with the clamping surfaces I8 by loosening the lock nuts 35 and adjusting screws 32 to the desired position, after which the lock nuts are again tightened to hold the screws in their selected positions of ad ustment.

Air pressure against the right jaw is now released by return of the foot pedal operated valve to its first position. The drawer sides 86 are now placed in position at each end of the drawer front, with the male dovetailed ends of the drawer sides in line with the female dovetailed ends ofthe drawer front. Air is applied once again to clamp the interengaging dovetails. The apparatus is now properly set up for clamping the drawer back. As a first step, the slide member 29 of each of the drawer side clamps is independently adjusted relative to the clamp bars 45 so that the clamping flange 46 of said bar 45 will not contact the side clamping bar 33 when pressure is applied to the overhead air cylinders 40. This adjustment is effected by loosening of the set screw 36, after which the nut is manually threaded upwardly or downwardl as necessary, until it is in the proper position.

The set screw 36 is now tightened once again.

The hand wheel 23 is now operated to lower the top and side clamping units, until the clamping bars 33 are approximately one inch below the back end of the drawer sides 66, which drawer sides will be vertically positioned during the assembly of the drawer so that the back ends the grooves. the clamping bars 45 will spring back to square position by action of the springs 48. When the clamping bar 33 is sprung backwardly to its previous position in this manner, it serves as an overhead clamping bar.

The operator now places the male dovetails of the drawer back in line with the respective female dovetails in the back end of 'thedrawer sides. Air is now applied to the overhead cylinders 40 and this results in clamping of the dovetails at both ends of the drawer back-squarely into position, the ram or plunger 4| forcing the member 42 downwardly which of course carries downwardly the overhead clamping flange 46.

Should the drawer be unusually long. the center rest 64 is employed, this being manually slid to a location wherein it is approximately centrally positioned between the jaws. The screw 62 is then utilized to force the center rest upwardly until it will support the center part of the drawer front to be clamped. after which the lock nut 63 holds the rest in its adjusted position.

As previously noted, there are spaced vertically aligned clamping surfaces I8, 19, and 20 on each jaw. In clamping of a flat front drawer, the surface [8 would be used in the manner previously noted. However, the additional clamping surfaces l9, and 20 make it possible to clamp a drawer with a half swelled front such as'illustrated in Fig. 11, or with a flat or straight front but with drawer sides of difierent lengths. Such a drawer is readily assembled, and in the illustrated example, one end of the drawer front is engaged by the clamping surface ll} of the right jaw, while the other end of the drawer front is located to receive its pressure from the clamping surface 20 of the left jaw. The rest 59 of the left jaw is adjusted upwardly a greater extent than the rest 59 of the right jaw. Despite this irregular jaw formation, the drawer back, which is located to receive pressure from the overhead cylinder 40, remains perfectly square with said overhead cylinders.

What is claimed is: v

1. In a drawer assembly machine a supporting frame; a pair of jaws mounted upon said frame for sliding movement toward and away from each other; standards upstanding from the respective jaws; feed screws rotatably and vertically mounted in the respective standards; a drawer back clamp slidably mounted upon the standard and having threaded engagement with said feed screw, for up and down adjustment of the drawer back clamp responsive to rotation of the feed screw; and a drawer side clamp slidably mounted upon the standard and having threaded engagement with said feed screw, for adjustment simultaneously with the drawer back clamp, said threaded engagement of the drawer side clamp being adapted for threaded adjustment of'the drawer side clamp upon the feed screw independently of adjustment of the drawer back clamp, for spacing the drawer side and drawer back clamps selected distances apart prior to simultaneous adjustment vertically of the standards.

2. In a drawer assembly machine a supporting frame; a pair of jaws mounted upon said frame for sliding movement toward and away from each other; standards upstanding from the respective jaws; feed screws rotatably and vertically mounted in the respective standards; a drawer back clamp including a slide member slidably mounted upon the standard and having threaded engagement with said feed screw, for up and down adjustment of the drawer back clamp responsive to rotation of the feed screw; and a drawer side clamp slidably mounted upon the standard and having threaded engagement with said feed screw, for adjustment simultaneously with the drawer back clamp, said threaded engagement of the drawer side clamp, being adapted for threaded adjustment of the drawer side clamp upon the feed screw independently of adjustment of" the drawer back clamp, for spacing the drawer side and drawer back clamps selected distances apart prior to simultaneous adjustment vertically of the standards, an air cylinder rigidly connected to the slide member; an air plunger extending from said air cylinder and having up and down movement independent of the vertical slidability .of the slide member; a second slide member slidably mounted upon the first slide member and engaged by said plunger; and a clamping bar pivotally connected to the second slide member for swinging movement in a vertical plane. said clamping bar including means yieldably retaining the clamping: bar in a position in which it is square with the second slide member.

JETER M. LANCASTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 987,531 Acldey Mar. 21, 1911 1,028,584 McKnight June 4, 1912 1,348,148 Bergstrom Aug. 3, 1920 1,602,684 Lancaster Oct. 12, 1926 1,733,284 Stiisak Oct. 29, 1929 1,842,147 Gardner Jan. 19, 1932 2,114,390 Lancaster Apr. 19, 1938 2,504,609 Williams Apr.18, 1950 

